Question

31. An element has 11 protons and 12 neutrons. Which of the following is true of a neutral atom of this element?

A. Its atomic number is 12 and mass number is 23.
B. Its atomic number is 23 and mass number is 11
C. Its atomic number is 11 and mass number is 23.
D. Its atomic number is 23 and mass number is 12.

Answer 1

C. It’s atomic number is 11 and mass number is 23
Because the atomic number is always the number of protons and the mass number is always number of protons + neutrons (since the electrons have little mass)

Answer 2

C.

Step-by-step explanation: